1. Navigate to this location:
%userprofile%AppDataLocalPackagesMicrosoft.Windows.ContentDeliveryManager_cw5n1h2txyewyLocalStateAssets
2. Copy all assets to a new folder
3. open cmd
4. navigate to the drive where you opened the new folder (example- type "c:")
5. type "cd <location of the new folder>"
6. type "ren *.* *.jpg" to rename all assets to jpg file
7. you will find the spotlight images among the assets